This document outlines statements from the Cambridge IGCSE Chemistry syllabus regarding electricity and chemistry. It describes key concepts such as defining electrolysis, describing the products and observations of electrolysis for various electrolytes, stating that metals form at the cathode and non-metals at the anode, relating products to electrolytes and electrodes, describing electrolysis in terms of ions and reactions, constructing half-equations, and predicting electrolysis products. It also describes electroplating, uses of materials in cables, the transfer of charge during electrolysis, producing electricity from cells, and manufacturing processes for aluminum and chlorine/hydrogen.

1. 08/04/2016
5. Electricity & Chemistry
Syllabus statements
Statements from Cambridge IGCSE Chemistry syllabus 0620 (for exams in 2016 – 2018)

2. Electricity & Chemistry
• Define electrolysis as the breakdown of an ionic
compound, molten or in aqueous solution, by the
passage of electricity
• Describe the electrode products and the
observations made during the electrolysis of:
– molten lead(II) bromide
– concentrated hydrochloric acid
– concentrated aqueous sodium chloride
– dilute sulfuric acid
between inert electrodes (platinum or carbon)

3. Electricity & Chemistry
• State the general principle that metals or hydrogen
are formed at the negative electrode (cathode), and
that non-metals (other than hydrogen) are formed
at the positive electrode (anode)
• Relate the products of electrolysis to the electrolyte
and electrodes used, exemplified by the specific
examples above, together with aqueous copper(II)
sulfate using carbon electrodes and using copper
electrodes (as used in the refining of copper)

4. Electricity & Chemistry
• Describe electrolysis in terms of the ions present
and reactions at the electrodes in the examples
given
• Construct ionic half-equations for reactions at the
cathode
• Predict the products of the electrolysis of a
specified binary compound in the molten state
• Predict the products of electrolysis of a specified
halide in dilute or concentrated aqueous solution

5. Electricity & Chemistry
• Describe the electroplating of metals
• Outline the uses of electroplating
• Describe the reasons for the use of copper and
(steel-cored) aluminium in cables, and why
plastics and ceramics are used as insulators

6. Electricity & Chemistry
• Describe the transfer of charge during electrolysis
to include:
– the movement of electrons in the metallic
conductor
– the removal or addition of electrons from the
external circuit at the electrodes
– the movement of ions in the electrolyte

7. Electricity & Chemistry
• Describe the production of electrical energy from
simple cells, i.e. two electrodes in an electrolyte.
(This should be linked with the reactivity series in
section 10.2 and redox in section 7.4.)

8. Electricity & Chemistry
• Describe, in outline, the manufacture of:
– aluminium from pure aluminium oxide in
molten cryolite (refer to section 10.3)
– chlorine, hydrogen and sodium hydroxide from
concentrated aqueous sodium chloride
(Starting materials and essential conditions should
be given but not technical details or diagrams.)